What is Sexsomnia?

Sexsomnia is a rare sleep disorder that causes people to engage in sexual behaviour while asleep. It is also known as “sleep sex” and was only added to the Diagnostic Statistical Manual of Mental Disorders (DSM-5) in 2013.

How is Sexsomnia Used in Court?

Sexsomnia is a recent version of an older legal defence known as automatism, which can be traced to the 1840s. Automatism describes actions without conscious volition (meaning without using your will). Those with automatism have no memory or knowledge of their acts.

The law has recognised automatism in sleep walking, in reflexes, spasms, or convulsions and in acts of those with hypoglycaemia (low blood sugar) and epilepsy. However, an important debate in the legal cases as well as among psychiatrists and sleep experts is about how to classify the condition.

Essentially, is sexsomnia a mental health impairment caused by an underlying mental illness? Or is it a temporary “malfunction” that occurs in an otherwise “healthy mind”?

How Can Sexsomnia Be Proved?

Detailed medical evidence is usually required for this defence. However, the defendant only needs to prove there was a “reasonable possibility” their acts were involuntary.

By contrast, the prosecution must prove “beyond a reasonable doubt” that the sexual acts were voluntary or “willed” – a higher standard of proof.

Is Sexsomnia a Mental Illness?

Some important Australian cases have considered whether the law should treat sexsomnia as an ongoing mental disorder instead of a transitory “malfunction of the mind”. In a 2022 case, prosecutors accepted that a New South Wales man accused of sexual offences against his daughter had sexsomnia. What they contested was that his condition arose from a “sound mind”.

They argued sexsomnia should now be considered a mental illness. This argument capitalised on new laws that had commenced that year in NSW. In defining mental health impairments, the new laws included a disturbance of volition.

Why is This Significant?

The 2022 case was understood to have legal implications – not only for NSW but for all state jurisdictions in Australia. If the prosecution could establish sexsomnia was a mental health impairment, then an outright acquittal would be unlikely.

Instead, the court would be required to reach a “special verdict” and might then refer the defendant to a mental health tribunal. As a result, the defendant could be detained in a secure psychiatric facility, such as the Long Bay Hospital.

Why Are These Definitions Controversial?

As long ago as 1966, legal scholars criticised how the law treats different kinds of automatism. While sleepwalkers and sexsomniacs are viewed as “perfectly harmless”, those with other conditions, such as schizophrenia, are viewed as “criminally demented” and detained in facilities under law.

Whether sexsomnia is a sleep disorder with non-recurring episodes or a more permanent mental disorder continues to be debated. However, the way it is addressed clinically may reinforce its status as a sleep disorder. As there are no formal practice guidelines for treatments, it has tended to be sleep clinics, rather than psychiatrists, who respond to the condition.

Conclusion

The increasing use of this rare condition as a defence in serious, violent cases of sexual assault is concerning and warrants further research and attention. The debate surrounding sexsomnia highlights the need for a nuanced understanding of this condition and its implications for the criminal justice system.

FAQs

Q: What is sexsomnia?
A: Sexsomnia is a rare sleep disorder that causes people to engage in sexual behaviour while asleep.

Q: How is sexsomnia used in court?
A: Sexsomnia is used as a defence in court, arguing that the defendant’s actions were involuntary due to the sleep disorder.

Q: Is sexsomnia a mental illness?
A: The debate surrounding sexsomnia is whether it is a mental health impairment caused by an underlying mental illness or a temporary “malfunction” that occurs in an otherwise “healthy mind”.

Q: How can sexsomnia be proved?
A: Detailed medical evidence is usually required for this defence, including proof that the defendant’s acts were involuntary.

Q: Why is this significant?
A: The 2022 case highlights the legal implications of sexsomnia and the need for a nuanced understanding of this condition and its implications for the criminal justice system.